DUBUS

DUBUS is the international bilingual, english and german, written magazine for Ham-Radio on VHF/UHF and Microwaves. The magazine is published quarterly in March, June, September and December. Each issue of over 100 pages, in A5, is devoted to a mix of state-of-the-art technical articles and DX operating news. National DUBUS representatives are in Austria, Australia, Belgium, Bulgaria, Canada, Czech Rep., Denmark, Eire, France, Finland, Greece, Italy, Japan, Netherlands, New Zealand, Norway, Portugal, Poland, Romania, Russia, Rep. of South Africa, Slovenia, Spain, Sweden, Switzerland, Ukraine, United Kingdom, USA.

DUBUS 1-2025 Vol-54

Editorial.
Building a Transverter Box for 10 GHz with 7W Output
by Ivan De Cesaris, IZ0JNY
In this article I document the project of a transverter box for 10 GHz, with a power output of 7W and feed integrated into the enclosure. I give all the technical information and the reference of each component ... [Project description | Dish feed | Coax relay | SSPA | Low-noise power supply| Enclosure | Assembly].
Large W2IMU Feedhorns for Improved G/T on Offset Dishes
by Paul Wade, W1GHZ
The W2IMU dual-mode feed has been popular for many years. It offers high performance and is relatively easy to make. The classic version, 1.31Lambda aperture diameter, offers best performance for a F/D around 0.5 to 0.6, which gives a pettern which is a bit wide for common offset dishes, leading to excess spillover which results in increased noise temperature. Still, it provides very good performance, particularly for terrestrial communications. In his original article, Dick Turrin, W2IMU, also described a large version, 1.86Lambda diameter. The large version is best for ... [Dual-mode feedhorn | Feed fabrication | G/T | Sun noise measurement | Comparison].
High Performance 1.9m Station for 23cm EME
by Bill Siino, KB2SA
Discussed here is a high performance 1.9m mesh wire dish station for 23cm EME. This paper helps quantify the extraordinary performance observed by some 23cm EME stations (e.g., KA1GT) and explores further enhancements to this performance. A key measure of performance is Antenna Gain divided by Antenna Noise Temperature (G/Ta). We wish to maximize this ratio for best ... [Why use a 1.9m dish | Loss budget | Simulation highlights | Feed design].
"WSPR Radar": Final Crash Landing of a windy Idea
by Nils Schiffhauer, DK8OK
In September 2021, Dr. Robert Westphal, former DARC chairman, presented his idea of using WSPR log data to locate aircraft. This found fervent and prominent advocates among his fellow club members as well as outspoken sceptics, first and fore most Nobel Prize winner Prof. Joe Taylor, K1JT, who was instrumental in developing WSPR. A long-announced study of the data on a statistical basis was finally published on January 1, 2025, and was supposed to give this "nonsense" a professorial blessing. But it was the last rites. DK8OK took a look around the crash site ... [Flight paths and path losses | SNR plots].
Versatile Programmable Microwave Source
by Goran Popovic, AD6IW
Frequency sources are fundamental building blocks for microwave and mm-wave frequencies. In the past they were based on low frequency ovened crystal oscillators and cascaded multipliers. Changing frequency was difficult, because it required another precision quarz crystal, and re-tuning of the multipliers. Phase noise and frequency stability were also issues. Digital and narrow band communications demand better stability and phase noise. Such improvements are possible with the new generation of fractional uW PLL synthesizers ... [ADF5356 data sheet | Circuit description | Construction].
10 GHz Booster for the IC-905
by Mauro Ottaviani, IZ1OTT
This article not only presents a project for the 10 GHz band but also aims to demostrate how the same concept can be effectively adaèted to develop similar systems across all microwave bands supported by the IC-905, including the forthcoming 24 GHz band, soon to be launched by Icom ... [Preamplifier | Power amplifier | Relay and cabling].
Tropo Reports.
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Microwave Europe.
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Microwave North America.
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